Brake drum grinder



ATTORNEYS.

Nov. 3, 1931.

A. P. STEINER BRAKE DRUM GRINDER Filed Oct. 16.

1928 7 Sheets-Sheet l Nov. 3, 1931. A. P. STEINER 1,830,723

BRAKE DRUM GRINDER Filed Oct. 16, 1928 7 sheets-Shet 2 iii;

INVENTOR. W was 9. s rcmcq.

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ATTORNEYS.

Nov. 3, 3931. A. P. STEIN'ER 1,

- BRAKE DRUM GRINDER Filed Oct. 16, 1928 7 Sheets-Sheet 3 lko - INVENTOR'. (was 2 STUNEQ BY I a ATTORNEYS.

Nov. 3, 1931. A. P. STEINER 1,830,723

BRAKE DRUM GRINDER Filed Oct. 16,1928 7 Sheets-Sheet 4 INVENTOR. mos P. STCWCR.

/7Z E5 5 BY x I ATTORNEYS.

' Nov. 3, T931.

A. P. STEINER' BRAKE DRUM GRINDER Filed Oct. 16, 1928 7 Sheets-Sheet 5 INVENTOR. AMOS P. STEJNEK.

A TTOR YS.

Nov. 3, 1931. A. P. STEINER 1,830,723

BRAKE. DRUM GR I NDER Filed Oct. 16, 1928 '7 Sheets-Sheet 6 & IN V EN TOR.

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\ T TORNEYS.

Patented Nov. 3, 1931 UNITED STATES PATENT OFFICE AMOS STEINER, OF WAYNESBORO, I'ENNSYLVANIA, ASSIGNOR- TO LAN DIS TOOL COM- IPANY, OF WAYNESBORO, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA BRAKE DRUM GRINDER Application filed October 16, 1928. Serial No. 312,903.

Another object is to provide means where-.

by the grinding operation is practically continuous, one piece of work being ground while a finished piece is being removed from the machine and an unfinished one placed in position to be ground.

A further general object is to provide in grinding machines for brake drums means which will greatly increase the capacity of the machine.

A further object is to provide in a grinding machine a wheel dressing device which is J movable lengthwise of the machine to positions to dress any one of a number of grinding wheels.

A further object is to provide av grinding machine with a control valve operable to control a number of machine operations in proper sequence.

Further objects and advantages will appear as the description proceeds.

Referring to the accompanying drawings, which are made a part hereof and on which similar reference characters indicate similar P Figure 1 is a front elevation of the machine,"

Figure2 is a sectional front view of one of the limit switches and the control therefor,

Figure 3 is chine,

Figure 4 is a plan view of the machine,

Figure 5, a plan view of the wheel base assembly,

Figure 6, a

an end elevation of the mafront elevation of the wheel 7 base assembly with certain parts shown in section,

Figure 7, a front elevation of the head stock assembly with part of the chuck mechanism shown in section,

- Figure 8, a section of the control valve taken on line 8-8 of Fig. 1,

Figure 9, a section through the control valve taken on line 9-9 of Fig. 8,

Flgure 10, a sectional View of the reversing valve for the wheel base taken on line 10l0, of Fig. 8,

Figure 11 is a section through the control valve showing the valve set in position to brlng the left work head to grinding position, and to withdraw the right hand work head, being a section on line 1111 of Fig. 8,

F1gure 12 is a section similar to Fig. 11, but showing the valve in position to withdraw both of the work heads,

Figure 13 is a section similar to Fig. 11, but showing the valve in position to bring the right hand work head to grinding position and towithdraw the left hand head, and

Figure 14 is a section similar to Fig. 9 but showing the position of the upper ports when the valve is in the position of Fig. 11.

In machines of this character heretofore used the operator was more or less idle while the work was actually being ground.

This machine provides structure whereby movement of a single central control lever will operate mechanism for withdrawing the head which carries a finished piece of work, moving the head carrying an unfinished piece of work to grinding position, and at the same time starting rotation of the work on this head, causing the wheel base to run in to grindin position, starting the flow of coolant on the rinding wheel, shifting the wheel guard to a low the wheel toenter the work and to cause all the above operations to take place in the proper sequence. Since the finished work is withdrawn from the grinding wheel and its rotation stopped it may be removed from the machine and a new piece inserted while the work in the opposite chuck is being ground. This enables an operator o do almost twice as much as could be done with a machine having a single work chuck.

In the drawings, reference character 20 in- The wiieel b ase assembly The wheel base 23 is mounted-on a slide base 24 which in turn is mounted upon a. wheel slide 25. The wheel base carries a shaft on the ends of which are mounted abrasive wheels 27 and 28. The shaft is driven by any suitable power mechanism, preferably by means of a belt 29 on a pulley 26 on the wheel shaft which belt passes around rollers 30 and 31 to a pulley 32 on a motor shaft. The grinding wheel shaft is given a recipro. cating movement by the following mechanism: In' a housing 34 mounted upon the. grinding wheel base 23 is a shaft 35 having a worm 36 preferably made integral therewith.

The outer end of the shaft carries a pulley 37. The worm 36 meshes with a; gear 38 mounted on a shaft 39. This shaft also carries an eccentric 40 which engages a cam following roller 41 on the upper end of an arm 42. This arm is pivoted at 43 on the grinding, wheel base. The lower end of the arm 42 is bifurcated and has pins securing it to reciprocating collar 44. This collar is held between washers 45 which are secured on. the wheel shaft. A thrust nut 46 serves as an adjustment for the collar 44 to take up play between the collar and the washers 45 at each side. This reciprocating mechanism is lubricated as follows: Lubricant from a circulating pump is directed upon the mechanism through a perforation 47 in the top of the housing 34 and passes down over the worm and work wheel to a dish 48 positioned beneath the gear wheel 38. A tube 49 positioned near the upper ,end of the dish 48 directs this lubricant into a small cup 50 extending out from the side of the arm 42. Itrom this cup the oil passes into a port 51 w1thm the arm 42 and thence around the collar 44 from which it drops to an oil reservoir in the base of the machine, not shown. The ulley 37 is driven by means of a belt 52 whic 0on nects with a pulley on a motor .53. As just stated, the wheelbase 23 is mounted on a slide base 24 which is mounted on a wheel slide 25. The wheel base is actuated by means'of a piston rod 54,which is secured to a bracket 55 depending from the under side of the wheel base. This rod has a piston 56 which operates in a cylinder 57 provided in the base of the machine. This cylinder 57 is provided with ports 58 and 59 for admitting and ex- I nected bylneans of a pipe 68 with a reservoir 69 through a needle valve 70. A manuall operable lever 71 provides means for adjustof the needle valve 70. The cylinder 66 therefore operates as a dash pot which limits rapid movement of the wheel basetoward the Work. When fluid under pressure is delivered through the port 58 to the cylinder 57 the wheel base is quickly moved toward the rear, the depending bracket 64 moving away from contact with the piston 65. A valve in the oil 'reservoir69 permits fluid from this reservoir to flow freely to the cylinder 66 to the chamber at the left of the piston 65 when so pressure fluid is delivered through the port 59 and exhausted from the port 58, pressure is then delivered to the right of the piston 56 .as shown in Figure 3 to move the grinding wheel base toward grinding position. The

first movement of the grinding wheel base will be rapid, and this rapid movement will continue until the bracket 64 comes into engagement with the piston 65. Movement of the grinding wheel then will be limited by the dash pot effect of the piston 65 with c linder 66. As theoil is forced up through t e pipe 68 past the needle valve 70 into the reservoir 69 the wheel base Will gradually be fed forward. The wheel is so positioned that it will be brought quickly to grindin position before the bracket 64 strikes t e piston 65.

The slop speed will be the grinding speed into the work as the stock is removed from the work by the abrasivewheel. The work cm-m'age and head stock assembly The work carriages 21 and 22 each carries a head stock to which are secured .work

chucks. As both work carriages are alike onl one will be described. As shown in Fig. 7 3 indicates a motor driven head stock equlpped with an air operated draw-in chuck for holding the work. This chuck comprises a chuck member 74 within which is secured no a work piece 7 5 here shown as a brake drum.

A centering and holding fixture 76 is posit1oned w1th1 n the drum and a clamping piece 77 acts. against this. centering fixture. The

clamping rod 78 is made integral with or secured to a piston rod 79 which is connected to a piston in an air operated cylinder, not shown. The piston 79 is controlled by means of an air valve 80 of well-known construction. When thevalve 80 is moved to op:

erative position, pressure fluid is delivered to the cylinder to hold the rod 79 to the left to secure the work securely clamped in the chuck. The work is rotated by means of a motor 81 which drives a pulley 82. The pulm5 ley 82 is 'operatively connected to the head stock spindle 83 so as to rotate the'work at a suitable speed, the operative connection y between the spindle 83 and the pulley 82 providing a greatly reduced speedto the said a line 112 acts against the plunger to move the switch to closed position. This pipe is connected to pipe 98. The motor 113 on the work carriage 22 is operated by a switch shown as a whole at 114. -Pressure fluid for operating this switch is delivered through pipe 115 which latter pipe is connected to pipe 104. Secured upon the head stock is a rod 84 which is adapted to engage and shift a bracket 85 to which bracket a wheel fender 86 is attached... The bracket 85 itself is slidably mounted on a bracket 87' which in turn is mounted on the wheel base 23. The bracket 85 has a forked portion 88 at one end. Screws 89 passing through the forks of the bracket 88 operate a lever 90 which controls a coolant valve 91. A spring 92 has one end hooked to the bracket 85 and the other end secured to the bracket 87 on the wheel base and serves to drive the wheel fender and water valve to inoperative position when the head stock has moved back away from the grinding wheel. The work carriages '21 and 22 are moved into and out of grinding position by means of fluid pressure as follows: Beneath each of the work carriages 21 and 22 are depending brackets 93 and 94. Secured to the bracket 93 is a piston rod 95 having a piston 96 movable in a cylinder 97. Fluid pressure conduits 98 and 99 are connected to opposite ends of the cylinder 97. A fluid conduit 100 is connected to the cylinder 97 adjacent the right hand end. Piston 101 and cylinder 102 with fluid conduit pipes 193, 104 and 105 provide fluid operating means for the other work head.

In order to move the work carriage 21 to grinding position and to withdraw the work carriage 22 from the work, fluid is delivered through the pipe 98 to cylinder 97 and pipe 103 to cylinder 102, and exhausted from these cylinders through pipes 99 and 104. In order to withdraw'the carriage 21 from grinding position and to move the carriage 22 into grindin position pressure fluid is delivered to cylinder 97 and 102 through pipes 99 and 104 respectively and exhausted from these cylinders through pipes 98 and 103 respectively. Coincident with withdrawing the work from the grinding wheel the grinding wheel base must be withdrawn and returned to the working position as the opposite work carriage moves its work into the sphere of action of the wheel. In order that the operator may remove the finished work from and place the new work 1n the withdrawn chuck, it is necessary that the motor which drives the work be stopped when the work carriage is withdrawn. I have therefore provided acentral control lever which operates a valve which controls admission of fluid to the cylinders which moves 1 the work carriages, admission of fluid to the cylinder which moves the wheel base. and which operates the switch which controls the work rotating motor. This valve assembly will now be described.

The control valve assembly The control valve is enclosed in a casing 116 which is secured to the front of the machine. Mounted within this casing is a con- .trol valve assembly shown as a whole at 117. Valve stems 118, 119 operate valves which control the flow of fluid through ports 120 and 121. Valve stem 122 controls a valve port at the right side of the valve assembly corresponding to valve port 120 shown in dotted lines in Figure 8. High pressure fluid line 123 leads from a pressure fluid supply in the base of the machine into a pressure chamber 124 within the control valve. From this chamber pressure fluid passes through valves 120 and 121 and the valve controlled bystem 122 to the several mechanisms which are operated by fluid pressure. Positioned within the casing 116 is the control valve itself, indicated as a whole at 125. This valve is seated upon a valve seat 126 which is provided with suitable ports which will be later explained. The valve is positioned within a valve housing 127. A fluid sealing ring 128 is positioned around the lower portion of the valve. A pipe 129 connects the high fluid pressure chamber 124 with a chamber 130 above the lower and large portion of the valve 125, in order to hold the valve upon itsseat. A spring 131 seated in a tang in the upper part of the housing and in a bore in the top of the valve acts with the pressure fluid in holding the valve upon its seat. The valve seat 126 is provided with ports 132 and 133, the port 132 being in communication through the needle valve 120 with the high pressure chamber 124, and the port 133 is connected,with the high pressure chamber 124'through a corresponding needle valve which is controlled by the valve stem 122. Ports 134 and 135 in the valve seat communicate with fluid lines 99 and 98 respectively. The latter fluid lines, it will be recalled, extend to opposite ends of the cylinder 97. Corresponding ports 136 and 137 on opposite sides of the valve seat communicate with fluid lines 103 and 104 which connect opposite ends of the cylinder 4 and 147 are two ports 149 and 150. A con-' necting passage 151 joins ports 146 and 145,

and a connecting passage 152 joins ports 147 and 144. v

The upper, smaller portion of the valve 125 shown as a whole at 153 is likewise provided with fluid ports. This upper section controls operation of the wheel base. This up r section contains two exhaust ports 154 and 155 which are connected directl to an exhaust lpassage 156 which in turn eads to the exaust passage 142 in communication with the exhaust pipe 143 which goes to the reservoir in the base of the machine. The pipes 100 and 105 which connect the cylinders 97 and 102 lead to the upper portion 153, of the valve 125. These pipes enter the valve through opposite sides of the valve housing 127. Two more pieces of tubing 157 and 158 enter the upper portion 153 just below the tubin 100 and 105. Each of the tubes runs to a T- oint, where they unite and enter the end of the automatic reversing valve 159. This valve controls admission of fluid to the cylinder 57 which erates movemeiit of the wheel base. This va ve is a piston valve having a port 160 in communication with high pressure fluid chamber 124 through needle valve 121. Ports 63 and 62 communicate with pipes 61 and 60 which enter the fluid cylinder 57 at opposite sides-of the piston 56. Ports 161 and 162 in the valve casing are connectedwith exhaust pipes which deliver fluid to the reservoir in the base of the machine. Pistons 163 and 164 control admission of fluid from the high pressure line 160 to either of the ports 63 and 62 as desired. A compression spring 165 is positioned a ainst the'piston 166 and tends to urge it to t e position shown in Fig. 10. When pressure fluid is admitted to the pressure line 157 the piston 164 is moved to the left to close the port 62 and open communication between ports 160 and 63. The valve 125 is operated by a handle 168 secured on a stem which extends up out ofthe casing 116.

Since it is necessary to use two grinding wheels to dress them when necessary.

-' is slidably mounted on A precision truing wheel 176 or a diamond wheels with a machine of this character, it is desirable to have a truing fixture which maybe moved lengthwise of the machine to position it before either of the grin d ihng 1s truing fixture consists of a bracket 170 which ideways 171 on the base of the machine. l his bracket is propelled along the machine by means of a hand wheel 172, gears 173 and 1 4 and arack 175.

may be mounted in the bracket 17 0.

Numeral 177 indicates. a work gage. It consists of an arm pivoted at178 and having a finger 17 9'extendmg into engagement .wlth

valve through the ports 132 and 133 and is directedthrough ports 134 an L136to the inner ends of eachof the cylinders 97 and 102, thus causing both' carriages to move back to inoperative position.

Figure 13 shows the valve 125 in position opposite to that shown in Fi roll and the operation of the machine-is t e same as that described above, except that the right hand head moves into the grinding '0S1tl0l1 and the left hand head is withdrawn.

The operation of the machine The operation of the machine is as follows Assume the machine to be in the position shown in Fig. 1, and that the work has been.

valves 118, 119 and 122.have been opened,

the operator then places a drum in position in the chuck 74 and clamps it in place by operating the air valve 80; He then moves .the lever 168 to the left, which is in the direction of the carriage which is to be moved to grinding position. This places the valve 125 in the position shown in Fig. 11, and the top of this valve in the position shown in Fig. 14. Pressure fluid from ressure cham- ,ber. 124 passes through nee le valve 121, through the port 132, through the slot 144, to the port 135 in the valve seat 126, and through this ort to the pipe 98 to deliver fluid to the le t of the piston 96. This moves the work carria e 21 into rinding position. Pressure fluid a so passes om pipe 98 into pipe 112 to close switch 106 and start the motor 81. Fluid at the same time passes from the high pressure chamber 124 through a needle valve controlled by valve stem 122 to the port 133 and through 136, from which it passes to a line 103 to the left of the piston 101. This moves the work carriage 22 back out of grinding position. Fluid in the cylinder 97 at the right of the piston 96 may exhaust through the pipe 99, port 134, exhaust port 138 to the exhaust ports 142 and 143. Fluid is exhausted from the right of the piston 101 through the line 104, port 137, exhaust .port 140 to the exhaust 142 and thence to 143. Fluid in the pipe 115 is likewise exhausted through pipe 104 to stop operation of the motor 113.- right end of the cylinder 97 the fluid line 100 is uncovered so that pressure fluid may pass into the line 100 from which it passes through the passage 169 in the upper portion; of the valve 153; thence through the pipe 157' to the end of the'plston 166 in thevalve 159.

s the piston 96 nears the This shifts'the pistons 163 and 164 to admit fiuid from the high pressure fluid chamher 124 through the port 160 to the port 63 to deliver fluid through the pressure line 6], to the right of the piston 56. This moves the wheel base quickly forward to grinding position. As soon as the bracket 64 strikes the end of the piston 66 the forward movement of the wheel base is checked and is limited by the needle valve 7 0 which allows fluid to be slowly forced up into the reservoir 69. The speed at which the grinding wheel then travels is the grinding speed with which the wheel moves into the work as the stock is removed from the work.

It will be obvious to those skilled in the art that various changes may be made in my device without departing from the spirit of the invention, and I, therefore, do not limit myself to what is shown in the drawings and described in the specification, but only as set forth in the appended claims.

Having thus fully described my said invention, what I claim as new and desire to secure by Letters Patent, is:

1. A grinding machine comprising a base, a grinding wheel support mounted upon said base, a work support, the said grinding wheel support having mounted therein a shaft/carrying a pair of grinding wheels, means formoving said grinding wheel support into and out of operative grinding position, means for moving the work support into and out of grinding position, means for rotating the work support, and a single control means for operating said grinding wheel support, said work support, and'for rotating said work support, substantially as set forth. I

2. A grinding machine having a wheel support and'a work support, the said wheel support having mounted therein a shaft having a grinding wheel mounted upon each end, the work support comprising a pair 0 head stocks, one mounted opposite each of the said grinding wheels, means formoving each of the head stocks into and out of grinding position, means for moving the said grinding wheel base into and out of grinding position, all the said means being con trolled by a single control lever, substantially as set forth.

3. A grinding machine comprising a grinding wheel support and a pair of work supports, the said grinding wheel support having a shaft rotatably mounted therein, and a. grinding wheel mounted upon each end, of said shaft, the said work supports being mounted one at each end of the machine and adapted to be moved into the sphere of action of the said grinding wheels, means for rotating the work in said work support, means for moving the work supporting heads alternatively into and out of grinding position, means for moving the grinding wheel support into and out of grinding position, and a single control means for all the said means, substantially as set forth.

4. In a grinding machine having a pair of work supports and a pair of grinding wheels, means for moving first one and then the other of the said work supports into grinding relation with the grinding wheel, and means simultaneously operated for moving the said grinding wheel out of and into grinding position, substantially as set forth;

5. A grinding machine comprising a pair of grinding wheels and a pair of work supports, means for moving the work supports alternatively into grinding position with respect to the grinding wheel, means simultaneously operated for moving the said grindingwheels out of and into operative grinding position, and means operated by movement of the said work support into grinding position for operating a coolant valve for the grinding wheel, substantially as set forth.

6. In a grinding machine having a pair of work supports and a pair of grinding wheels, means for moving first one and then the other of the said work supports into grinding relation with the grinding wheel, means simultaneously operated for moving the said grinding wheel out of and into grinding position, and means for reciprocating the said grinding wheels, substantially as set forth.

7. A grinding machine comprising a pair of grinding wheels and a pair of work supports, means for moving the work supports alternatively into rinding positionwith respect to "the grin ing wheel, means simultaneously operated for moving the-said grinding wheels out of and into operatively grinding position, means operated by movement of the said work support for operating a coolant valve for the grinding wheel, and means f for reciprocating the said grinding wheels,

substantially as set forth.

8. A grinding machine comprisinga base, a pair of work carriages mounted upon said base, head stocks mounted upon said work carriages, means for rotating said head stocks, a wheel base, means for moving said wheel base into and out of grinding position, means for moving the said head stocks alternatively into and out of grinding relation with the grinding wheels, a control Valve'for said last named means, the said control valve controlling also movement of the said wheelbase, and the rotation of the said head stocks, .substantially as set forth.

9. In a grinding machine having a pair of grinding wheels and a pair of work supports means for alternatively mo ing the work supports into the sphere of action of the grinding wheels and simultaneously causing rotation of the work on the work support as the work comes into grinding position,

and for stopping rotation of the work on the opposite work support as the work support is moved out of position, substan I tiallly i; set :Eortdl:ilg hm h '0. agrin' mac'e avinga air of grinding wheels and a pair of opposi eully positioned work supports means for sim taneously moving one work support into the sphere of action of the grinding wheel and 10 moving the" other work support away from the grinding wheel and causing the flow of cooling flmd upon the grindm wheel to which the work sup rt has move and shutj ting 05 the flow 0 coolant from the other grinding wheel, substantially as set forth.

In witness whereof, I have hereunto setm hand at Waynesboro, Pennsylvania, this 15th (1 y of October, A. D. nineteen hundred and I twenty-eight. 2o -AMOS B. STEINER. 

